What should you know about knee very swollen after fall?

Swelling that appears quickly after a fall can occur when the joint is irritated or when blood collects inside it. A forceful landing may also affect the meniscus, ligaments such as the ACL, or a bone. Swelling over the kneecap can involve a bursa, while arthritis or gout may flare after an otherwise modest injury. Knee swelling is a symptom rather than a diagnosis. Tell the clinician how you landed, whether you heard a pop, and whether the knee locked, gave way, or became difficult to straighten.

Stop the activity and protect the knee from further impact. Rest it in a comfortable position, elevate the leg, and use a wrapped cool pack for short periods. Avoid heat, deep massage, kneeling, and forceful stretching during the early phase. Do not test the knee repeatedly by twisting or jumping. If walking is painful or unstable, use support and arrange an assessment; a clinician may consider an examination and imaging. Joint aspiration is sometimes used to remove fluid and help clarify what is inside the joint, but it is not suitable for everyone.

Seek urgent care if the knee looks deformed, you cannot bear weight, the foot is numb or unusually cold, or the swelling is rapidly worsening. Immediate assessment is also appropriate for severe pain, an open wound near the joint, fever with a hot red knee, or a knee that cannot move. These features can indicate a fracture, major internal injury, infection, or a circulation problem.

Ask which structures may have been injured, whether imaging is needed, how much weight you can place on the leg, and which signs should prompt urgent review. You can also ask whether fluid removal or physiotherapy may help after the diagnosis is clearer.